2An Early History of BiopsychologyPlato: the mind is located in the brainFranz Gall and PhrenologyEarly 1800sRead bumps on skull to understand traits

3Biopsychology TodayEverything we do is ultimately controlled by our body and brainBody/brain composed of cellsBrain cells called neurons communicate electrically and chemicallyDifferent parts of the brain have specific functionsOur brains create meaningful experiences from sensory informationBrain structure and function is influenced by experience

4Neurons: Defining and TypesA NEURON is a nerve cell.There are three basic types of neurons (diagram):Sensory Neurons: Afferent neurons that detect stimuli from sense organs and relay this information TO the brain and/or spinal cord.Motor Neurons: Efferent neurons that receive signals from the brain and/or spinal cord and relay this information to glands and muscles.Interneurons: neurons in the brain and spinal cord that coodinate activity between sensory and motor neurons.Three Types of Neurons in action!Glial Cells: provide nutrients to neurons, insulate neurons, and remove debris when neurons die.

6The Neural Impulse (diagram)Intraneural transmission: within on neuronThis is an ELECTRICAL processOccurs as a result of the exchange of charged particles called ions

7Neural Impulse: Resting PotentialWhen more negative ions are inside the neuron than outsideNeuron is not transmitting informationSimilar to a compressed springThe neuron is POLARIZED – meaning it has a charge (-)System WANTS to reach equilibrium and balance charges, but selectively permeable membrane is closed when in this state known as resting potential

9Neural Impulse: All-or-None LawA neuron either fires or it does notWhen it does fire, it will always produce an impulse of the same strengthIntensity of a stimulus is coded by the frequency of action potentials or the number of neurons that fireIn other words, if there are several neighboring neurons firing, or one neuron firing repeatedly, the stimulus may be intense enough for the neuron to fire.

10Neural Impulse: RefractoryAbsolute refractory periodPeriod immediately after an action potential when another action potential cannot occurRelative refractory periodPeriod following absolute refractory period when a neuron will only respond to a stronger than normal impulseDuring the refractory period, the neuron is trying to get back to resting potential by pumping out K+ ions!

11So…? Impulse has traveled down the length of the axonSignal end up at terminal buttons, very end points of the axon terminalsThen what?Signal must get to other neurons, but how?

12The Synapse (diagram) The synapse Synaptic space (synaptic cleft)Composed of the terminal button of one neuron, the synaptic space, and the dendrites or cell body of the receiving neuronSynaptic space (synaptic cleft)Tiny gap between neuronsMessages must travel across the space to get from one neuron to the next

13Transmission Between NeuronsPresynapticNeuronInterneural: between neuronsa CHEMICAL processSynaptic vesiclesSacs in terminal button that release chemicals into synaptic spaceNeurotransmittersChemicals released by synaptic vesiclesReceptor sitesLocation on receptor neuron for specific neurotransmitterLock and keyReuptake“Recycling” neurotransmittersPostsynapticNeuron

15Neurotransmitters and Behavior (diagram)Neurotransmitters regulate many aspects of behaviorAn imbalance of neurotransmitters may cause maladaptive behaviorNeurotransmitters may be inhibitory, excitatory or both

16Drugs and NeurotransmittersDrugs’ impact on the body has helped scientists discover neurotransmitters, neuropeptides (e.g. amino acids such as endorphins) and neuromodulators that can increase or decrease the activity of certain neurotransmittersHow do drugs work?Agonists mimic or prevent reuptake (1, 3)Antagonists block neurotransmission (2)

17Psychopharmacology BotulismBlocks release of ACh at the neuromuscular junction, causing paralysis“Botox” is botulism toxin used to prevent facial muscles from making wrinklesCurare – found in vines in S. America; used as poisonCan stun or kill prey quicklyBlocks ACh receptors causing paralysisAntipsychotic medicationsBlock dopamine receptorsReduces schizophrenic hallucinationsCaffeineIncreases the release of excitatory neurotransmitters by blocking the inhibitory neurotransmitter adenosineCocainePrevents reuptake of dopamineLeads to heightened arousal of entire nervous system

18Endocrine System + Nervous System= Two Peas in a Pod?All of our physical and emotional reactions are the product of communication between the brain and the rest of the bodyEndocrine System = Glands (hormones)Nervous System = NeuronsOur brain is the “supercomputer” and may instruct our glands to release hormones AS IT IS instructing the neurons in the central and peripheral nervous systems to fireExample: You are being chased by a bear!Brain -> Endocrine- Release adrenaline from adrenal glandBrain -> CNS- communicate via epinephrine (NT) to excite SNS

19The Endocrine System (diagram)Tell me about it!I hate being naked in front of all these students…Helps coordinate and integrate complex psychological reactionsEndocrine glands secrete hormones into the bloodstreamHormones serve to organize the nervous system and bodyHormones also activate behavior, such as sexual behavior, hunger and aggressionSlower communication than Nervous System (but impacts last longer)

24Central Nervous System (CNS)BrainSpinal CordBrainEnables all functioningBillions of neurons and their connectionsThese neurons work together in neural networks to facilitate efficient output.As we learn, these networks strengthenSpinal CordConnects brain to PNSHandles reflexesI rule.

25The Brain Without our brains, we would really be nothing!“The mind is what the brain does”Brain + Body = MindWe live somewhere “north of the neck”What would happen if our brains were placed into another human’s body?

28Studying the Brain: Functional Neuroimaging TechniquesPET (positron emission tomography)Image created by the rate at which radioactive glucose is metabolizedWhich areas of the brain are active during a particular activityfMRI (functional MRI)Combines structural and functional techniquesMultiple images of brain created during a particular taskRecords changes in blood flow to indicate regions of greater activity

29Primitive Brain StructuresBrainstemOldest part of brainContains medulla, controlling heartbeat, blood pressure and breathingAlso contains pons, which helps regulate sensory information and facial expressionsContains Reticular Formation (RF) for alertness/arousal, sleep/wakefulnessThalamusPair of egg-shaped structures on top of brainstemRoutes all incoming sensory information except for smell to appropriate areas of brainCommunicates with higher level of brainPenn StationCerebellum“little brain” at read of brainstemControls coordination, balance, and muscle toneThese parts of the brain are our “autopilot” so other regions can deal with higher-level “human” functions

30The Limbic SystemLocated in between the primitive parts of the brain and the cerebral hemispheresHippocampus processes new memories (case of H.M.)Amygdala controls emotions such as aggression and fear – in animals, the “attack” response (rat study)Hypothalamus regulates hunger, thirst, body temperature and sex drive – also controls pituitary glandRat study – self-stimulation of “pleasure centers”Human implications? Mild pleasure, addiction tendencies?Primarily, the limbic system processes drives, smell and various emotional responses

31The CortexPart of the cerebrum, the two large hemispheres comprising 85% of brain weightWrinkled outer layerWhy so convoluted?Higher level functionsDesignation of cortical space and “higher level” animals?Most highly evolved part of the human brain

32Cortex Breakdown… Each hemisphere is divided into 4 lobesFrontal lobeTemporal lobeParietal lobeOccipital lobeThe lobes are separated by deep convolutions known as fissures

38Neurogenesis?Recent evidence has suggested that human brains may be able to generate new brain cells, known as NeurogenesisStem cell research?

39The Two Hemispheres Two halves are NOT identicalMost have a dominant hemisphere – usually the left, which controls the right side of the bodyBoth sides serve important functions, revealed by studying split-brain patients

40Split-Brain Epilepsy, seizures and the corpus callosumReduction in epileptic seizuresDifferent abilities in each hemisphereThe story of “Vicki”Michael Gazzaniga

41Some Hemispheric StrengthsLeft HemisphereLanguage in most people: The cases of Ta of Charles LandryLogicRight side of bodyRight HemispherePerceptionSense of selfInferences

42Hemispheric Dominance: Handedness90% of humans are right-handedThe 10% of left-handers show less predictable patterns of hemispheric dominanceCauses?Genetics?Fetal testosterone levels?Learned?Handedness and sexual orientation?A closer look: a curse or an advantage?

43Behavior Genetics: What’s the Point?Behavior Genetics seeks to understand the relative influence of our heredity and our experiencesNature vs. Nurture? It’s both – but how much of each?

44Behavior Genetics: Genetics ReviewHeredity examines the transmission of trait from one generation to nextChromosomesPairs of thread like bodies that contain genesAverage human cell has 23 pairsSex cells?Deoxyribonucleic acid (DNA)Organic molecule arranged in a double-helixContains the “code of life”GenesBasic units of inheritanceSegment of DNAGenome“map” for an organism’s genetic complete make-upHuman Genome Project

46Behavioral Genetics: Temperament and HeritabilityTemperament refers to emotional reactivity and seems to be set very early in lifeThomas and Chess (easy, difficult, slow-to-warm-up)Kagan’s “shy child”Indicates this aspect of behavior is genetically manipulatedEnvironment can enhance or diminish this genetic predisposition

47Behavior Genetics: HeritabilityHeritability: the extent to which differences among organisms are caused by genesDoes NOT refer to which percentage of a trait is determined by genetics in a given individual!The more similar and controlled the environment of the organisms is, the more we can attribute differences to genes, and the higher the heritability!

49Evolutionary PsychologyWhereas behavior geneticists seek to explain our behavioral differences in terms of our genes, evolutionary psychologists focus on our similarities, as dictated by natural selection.Richard Dawkins The Selfish Gene (1976)Varied organisms in a population compete to surviveCertain biological and behavioral variations facilitate survivalSurviving organisms may reproduce and pass on their genesThis leads to overall changing characteristics in a population

50Evolutionary Psychology: Natural Selection, Adaptation and Evolutionary SuccessSelection – providing a reproductive advantage, either naturally or artificially (e.g. tame foxes), based on a trait/set of traitsThese traits will endure over timePopulation will change as a resultVariation can result from mutations (errors in genetic replication right after conception)Some of these “errors” provide an advantage and are selected for, and therefore persistThe errors are adaptive – increasing our fitness, or our chances to survive (and to reproduce)Humans have so many shared characteristics – How?Differences that were not “fit” were not passed onThose that increased survival were, as these organisms lived and reproduced

52Evolutionary Psychology: Explaining Human Sexuality and MatingMales of all sexualities generally are more interested in sex, regard sex as a recreational activity and prefer young, attractive matesFemales of all sexualities generally see sex as an outgrowth of relationships and prefer mature, stable, and affluent matesHave these trends genetically motivated?

53Evolutionary Psychology: Human Sexuality and MatingWomenQuality over quantityMore invested in bearing/nurturing childrenSeek men who either provide superb genes (he-man strategy) or are good providers (domestic-bliss strategy)“fast” vs. “coy” femalesMenQuantity over qualityIncrease reproductive success by spreading their genes as widely as possibleAttraction to fertile femalesNot physically bound to pregnancyHe-man strategy vs. opportunistsPhilanderers vs. Stable males?Perhaps males should invest more in child-rearing?

54Evolutionary Psychology: CriticismDo these arguments just provide excuses for bad behavior?Do humans have more of a social and cultural responsibility to make the world better?What about environmental influence?How does the environment reinforce these trends?How much of a role does environment play in the persistence of these roles?Who benefits?

55Parents and Peers Experience and Brain Development Parental Influence?Critical Periods – “Use it or lose it”Rosenzweig revisitedBrains are shaped by our genes AND experience- Lines and colors on a coloring pageParental Influence?If abusive or neglectful, can have major impactIn non-extreme cases, parents probably deserve less credit, or less blame!Parents shape values, beliefs and habits, but not as much as we may believeMost important to provide unconditional love and supportPeer InfluencePeers teach us how to socialize and cooperateSelection effect: seeking peers with similar interests

56Cultural Influences Culture Normsdistinctive values, beliefs, language and characteristics of a societyboth tangible (food, clothing) and intangible (values, beliefs).NormsRules that represent the typical behaviors of a particular groupOne example is expected personal space, the distance we like to keep ourselves from other people

57Class Poll- ANSWER HONESTLY: The worst that can happen is that you’ll be judged harshly….. Not.Do you base your self-perception on the traits you possess (athleticism, looks, intelligence) or on your sense of belonging (relationship with friends/family)Do you define success as performance in career or in terms of the relationships you form and the roles you fulfill.The most important thing about a marriage is personal happiness. (T/F)You see a froshie being teased by a group of girls for the shirt she’s wearing. The girls don’t think she heard, but you know she did. Do you step in or mind your own beeswax?Popularity is based ona) quality of friendshipb) amount of friends.Your behavior (success included) is controlled by who you are and what you want to do. (T/F)

58Individualism vs. CollectivismIndividualist cultures place value of singular person over that of the groupCollectivist cultures value the group over the individualWhich type of culture does the US have? Why?Implications?

59Gender Development Aggression, Power, and ConnectednessAggression involves an intent to harm, whether verbal or physical: males admit to and exhibit more than females.Men are and are perceived as more powerful and engage in behaviors that exhibit and perpetuate this power inequity.Females place greater emphasis on social connections, choosing careers that involve social interaction or require nurturing rolesMales have more difficulty admitting they are wrongWomen internalize emotions and behavior; Men see the source of the problem as external

60Why Are We Different? Biological ExplanationsX and Y ChromosomesY triggers sex differentiation during fetal development, causing greater testosterone production in malesFemale infants exposed to elevated levels of testosterone exhibit “male” behavioral characteristicsTom boy!Males with normal male hormones but had their sex reassigned at birth for various reasons often embrace a male identity, despite efforts to raise them as females

61Why Are We Different? Social ExplanationsGender Roles – expected behaviors for males and femalesWomen as caregivers?Men as breadwinners?The Reality? Women now OUTNUMBER men in the workplace in the US, yet in 87% of families with children, are still the primary caregivers.Variations across culture and time…Gender Identity – our sense of being male or femaleGender typing – embracing a traditional masculine/feminine roleSocial Learning Theory and Gender SchemasClose contact, imitation of superiorsLearn about what it means to be male/female from cultureWhat do these roles and stereotypes provide for us?Sense of stability and simplificationSense of confinementFluidity of gender?

62Nature vs. Nurture? Call the Whole Thing Off!Our genes and our experiences form usFamily, friends, and culture have an influence over the genes that make usThese structures are constantly in fluxWe are adaptive creaturesThe world changes, and we change with it